However ViaForensics (the company hired by Channel 4 News to do the leg work) has today demonstrated that it can lift the customer's name from any Visa-branded card.

That's important because without the name even Amazon won't process payments. Retailers generally check the CVV code (the three-digit number on the back), which isn't stored on the card chip so it can't be lifted, and reputable shops should check the cardholder's address too. However Amazon was caught skipping both those checks when the telly newshounds probed earlier this week.

Barclays told the programme that sharing the name was in an early, but still valid, version of the proximity-payment standard. Barclays was an early adopter of pay-by-bonk tech, and claims that sharing the name isn't a significant security risk anyway: "If a retailer is processing payments without CVV codes, the name isn't probably going to make a lot of difference," the bank claimed.

Channel 4 News will cover the story this evening, at 7PM BST but the details are already on its site. ®